How is 'Chanda' (Intention) related to 'Tanha' (Desire)?

How is 'Chanda' (Intention) related to 'Tanha' (Desire) ? I often hear that Karma is determined by intention. I want to know how they are all related. What comes first? What gets abandoned in meditation and Nirvana? I know of a YouTuber who claims to have gotten Nirvana, but he said after some time he had to train himself to purposefully generate an intention to talk and explain things to other people. So did he also have a prior desire to help other people? How this three work for Enlightened people and seekers?